Files
2026-07-09 18:16:06 +09:00

61 lines
1.9 KiB
Python

from torch import nn
from torch.nn import init
def weights_init_kaiming(m):
classname = m.__class__.__name__
# print(classname)
if classname.find('Conv') != -1:
init.kaiming_normal_(m.weight.data, a=0, mode='fan_in')
elif classname.find('Linear') != -1:
init.kaiming_normal_(m.weight.data, a=0, mode='fan_out')
init.constant_(m.bias.data, 0.0)
elif classname.find('BatchNorm1d') != -1:
init.normal_(m.weight.data, 1.0, 0.02)
init.constant_(m.bias.data, 0.0)
def weights_init_classifier(m):
classname = m.__class__.__name__
if classname.find('Linear') != -1:
init.normal_(m.weight.data, std=0.001)
init.constant_(m.bias.data, 0.0)
# Defines the new fc layer and classification layer
# |--Linear--|--bn--|--relu--|--Linear--|
class ClassBlock(nn.Module):
def __init__(self, input_dim, class_num=1, activ='sigmoid', num_bottleneck=512):
super(ClassBlock, self).__init__()
add_block = []
add_block += [nn.Linear(input_dim, num_bottleneck)]
add_block += [nn.BatchNorm1d(num_bottleneck)]
add_block += [nn.LeakyReLU(0.1)]
add_block += [nn.Dropout(p=0.5)]
add_block = nn.Sequential(*add_block)
add_block.apply(weights_init_kaiming)
classifier = []
classifier += [nn.Linear(num_bottleneck, class_num)]
if activ == 'sigmoid':
classifier += [nn.Sigmoid()]
elif activ == 'softmax':
classifier += [nn.Softmax()]
elif activ == 'none':
classifier += []
else:
raise AssertionError("Unsupported activation: {}".format(activ))
classifier = nn.Sequential(*classifier)
classifier.apply(weights_init_classifier)
self.add_block = add_block
self.classifier = classifier
def forward(self, x):
x = self.add_block(x)
x = self.classifier(x)
return x